PHASE EQUILIBRIUM AND INVESTIGATION OF X-RAY AND ELECTRO-PHYSICAL PROPERTIES OF SOLID SOLUTION ALLOYS IN THE Pb2Ga2s5–YbGa2S4 system

The character of chemical interaction of Pb2Ga2S5 and YbGa2S4 compounds was studied and the T-x phase diagram of the Pb2Ga2S5-YbGa2S4 system was constructed using the methods of physicochemical analysis: differential thermal analysis (DTA), X-ray phase analysis (XRD), microstructural analysis (MSA), as well as methods for determining microhardness and density. It was found that the Pb2Ga2S5-YbGa2S4 system is a quasi-binary section of the quasi-ternary PbS-Ga2S3-YbS system and belongs to the eutectic type. The composition of the eutectic formed between the Pb2Ga2S5 and YbGa2S4 compounds is 30 mol. % YbGa2S4, the temperature is 625°C. A wide region of solid solution based on both components at room temperature was found in the Pb2Ga2S5-YbGa2S4 system. It was found that at room temperature in the system based on the Pb2Ga2S5 compound the solubility reaches 12 mol. % YbGa2S4, and in the system based on the YbGa2S4 compound - 18 mol. % Pb2Ga2S5. X-ray structural analysis of solid solution alloys (YbGa2S4)1-x(Pb2Ga2S5)x (x=0.03; 0.05; 0.10) was carried out and their lattice parameters were calculated. The temperature dependence of electrical conductivity and thermo-EMF of solid solution alloys ((YbGa2S4)1-x(Pb2Ga2S5)x (x=0.01; 0.03; 0.04; 0.05) formed in the system was studied. Solid solution alloys are semiconductor materials with high resistance